The invention relates to continuously variable speed transmissions in general, and more particularly to improvements in transmissions of the type wherein an endless flexible element is trained over two sheaves to transmit torque from an engine or another suitable torque applying device to a driven unit, e.g., in a motor vehicle. Still more particularly, the invention relates to improvements in transmissions of the type wherein at least one of the sheaves comprises an axially fixed and an axially movable flange and the movements of the axially movable flange are controlled, at least in part, by a torque sensor.
It is already known to provide a continuously variable speed transmission of the above outlined character with a torque sensor wherein spherical rolling elements are confined between two ramps serving to generate twisting and/or pressing forces in dependency on the torque and/or transmission ratio. Reference may be had, for example, to published German patent application Serial No. 28 46 546 wherein the rolling elements of the torque sensor are distributed in such a way that the rolling elements are not invariably capable of moving along the adjacent surfaces of the ramps. This results in the development of certain hysteresis which can adversely influence the operation of the transmission.